C. Jason Woodard

Innovation in the Programmable Web: Characterizing the Mashup Ecosystem

This paper investigates the structure and dynamics of the Web 2.0 software ecosystem by analyzing empirical data on web service APIs and mashups. Using network analysis tools to visualize the growth of the ecosystem from December 2005 to 2007, we find that the APIs are organized into three tiers, and that mashups are often formed by combining APIs across tiers. Plotting the cumulative distribution of mashups to APIs reveals a power-law relationship, although the tail is short compared to previously reported distributions of book and movie sales. While this finding highlights the dominant role played by the most popular APIs in the mashup ecosystem, additional evidence reveals the importance of less popular APIs in weaving the ecosystems rich network structure.

Design capital and design moves: the logic of digital business strategy

As information technology becomes integral to the products and services in a growing range of industries, there has been a corresponding surge of interest in understanding how firms can effectively formulate and execute digital business strategies. This fusion of IT within the business environment gives rise to a strategic tension between investing in digital artifacts for long-term value creation and exploiting them for short-term value appropriation. Further, relentless innovation and competitive pressures dictate that firms continually adapt these artifacts to changing market and technological conditions, but sustained profitability requires scalable architectures that can serve a large customer base and stable interfaces that support integration across a diverse ecosystem of complementary offerings. The study of digital business strategy needs new concepts and methods to examine how these forces are managed in pursuit of competitive advantage. We conceptualize the logic of digital business strategy in terms of two constructs: design capital (i.e., the cumulative stock of designs owned or controlled by a firm) and design moves (i.e., the discrete strategic actions that enlarge, reduce, or modify a firms stock of designs). We also identify two salient dimensions of design capital, namely, option value and technical debt. Using embedded case studies of four firms, we develop a rich conceptual model and testable propositions to lay out a design-based logic of digital business strategy. This logic highlights the interplay between design moves and design capital in the context of digital business strategy and contributes to a growing body of insights that link the design of digital artifacts to competitive strategy and firm-level performance.

Using interactive evolutionary computation (IEC) with validated surrogate fitness functions for redistricting

We describe a novel use of evolutionary computation to discover good districting plans for the Philadelphia City Council. We were able to discover 116 distinct, high quality, legally valid plans. These constitute a rich resource on which stakeholders may base deliberation. The exercise raised the issue of how to deal with large numbers of plans, especially with the aim of avoiding gerrymandering and promoting fairness. Interactive Evolutionary Computation (IEC) is a natural approach here, if practicable. The paper proposes development of Validated Surrogate Fitness (VSF) functions as a workable and generalizable form of IEC.

Managing Technical Debt: Insights from Recent Empirical Evidence

Technical debt refers to maintenance obligations that software teams accumulate as a result of their actions. Empirical research has led researchers to suggest three dimensions along which software development teams should map their technical-debt metrics: customer satisfaction needs, reliability needs, and the probability of technology disruption.

Strategic Responses to Standardization: Embrace, Extend or Extinguish?

Prior research on technology standardization has focused on two common patterns: processes in which product developers and other stakeholders cooperate to achieve a consensus outcome, and “standards wars” in which competing technologies vie for dominance in the market. This study examines Microsofts responses to 12 software technologies in the period between 1990 and 2005. Despite the companys reputed tendency to pursue a strategy dubbed “embrace, extend, and extinguish,” a content analysis of news articles from the same period reveals surprising diversity in Microsofts responses at the product level. We classify these responses using a typology that treats “embrace” and “extend” as orthogonal decisions faced by product development organizations. This typology allows four kinds of outcomes to be distinguished, including two kinds of partial compatibility in addition to the familiar cases of full compatibility and incompatibility. To complement this cross-sectional perspective, we examine more closely the evolution of Microsofts strategy with respect to Suns Java technology. This longitudinal view highlights another underappreciated aspect of standardization, namely the extent to which a firms strategic posture toward a standard can change over time, even within the same product family. Based on this evidence, we suggest that firms tend to publicly embrace a standard with the aim of gaining legitimacy with a community of adopters, whereas efforts to extend a standard tend to be motivated by the intent to leverage the underlying technology to achieve or strengthen architectural control. We argue that legitimacy and leverage are strategic complements, making the “embrace and extend” strategy attractive to firms like Microsoft, but that the resulting outcome is unstable. Firms that pursue this strategy ultimately face a choice between contributing their extensions back to the standard and losing proprietary leverage, or giving up the legitimacy associated with standards compliance in exchange for freedom from the constraints of compatibility.

On Empirical Validation of Compactness Measures for Electoral Redistricting and Its Significance for Application of Models in the Social Sciences

Use of optimization models in science and policy applications is often problematic because the best available models are very inaccurate representations of the originating problems. Such is the case with electoral districting models, for which there exist no generally accepted measures of compactness, in spite of many proposals and much analytical study. This article reports on an experimental investigation of subjective judgments of compactness for electoral districts. The experiment draws on a unique database of 116 distinct, legally valid districting plans for the Philadelphia City Council, discovered with evolutionary computation. Subjects in the experiment displayed, in the aggregate, remarkable agreement with several standard measures of compactness, thus providing warrant for use of these measures that has heretofore been unavailable. The exercise also lends support to the underlying methodology on display here, which proposes to use models based on subjective judgments in combination with algorithms that find multiple solutions in order to support application of optimization models in contexts in which they are only very approximate representations.

Modeling technology evolution using generalized genotype-phenotype maps

Modeling open-ended technological evolution is notoriously challenging. The most successful models to date have been grounded in specific domains such as electronic circuit design. This paper presents an alternative approach based on a generalization of Kauffmans NK model. In this approach, boundedly rational agents combine components into products and systems whose value is determined by a random fitness landscape in which components may vary in their pleiotropy, or the number of genotypic functions they enable. The authors are developing a family of agent-based models using this framework, the first of which explores the evolution of platform architectures. Preliminary results from this model show that platforms emerge most strongly under conditions of frequent but moderate environmental change or a moderate number of correlated market niches.